The use of substituted aminomethyl-2,3,8,9-tetrahydro-7H-1,4-dioxino[2,3-e]indol-8-ones as dopamine D2 receptor agonists has been described, for example, in U.S. Pat. No. 5,756,532. That patent further provides methods for synthesizing such compounds; however, the methods described therein suffer from certain disadvantages, including the low yield and the large number of purification steps required.
Accordingly, there is a need in the art for improved methods for synthesizing substituted aminomethyl-2,3,8,9-tetrahydro-7H-1,4-dioxino[2,3-e]indol-8-ones. The present invention fulfills this need, and provides further related advantages.